Compost Calculator

Calculate your compost C:N ratio and get adjustment recommendations for optimal decomposition.

Bin Size
lbs
lbs

Current C:N Ratio

50:1

Needs Adjustment

Ideal range: 25:1 – 30:1

Adjustment

Add 120.0 lbs more greens

Est. Finish Time

4–6 months

Greens

25%

Browns

75%

Common Greens (Nitrogen-Rich, ~20:1)

Fruit/vegetable scraps~15:1
Fresh grass clippings~17:1
Coffee grounds~20:1
Fresh manure~15:1

Common Browns (Carbon-Rich, ~60:1)

Dry leaves~60:1
Cardboard~350:1
Straw~75:1
Wood chips~400:1
Newspaper~175:1

Temperature Monitoring

Active Phase130–160°F (kill pathogens & weeds)
Curing Phase80–110°F (stabilizing)
ReadyAmbient temp, earthy smell
Too Hot (>170°F)Turn pile, add water

C:N ratios are approximations — actual values vary by material. Turn your pile every 1–2 weeks and maintain moisture like a wrung-out sponge for best results.

Use the Compost Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.